/in/foo.cc: In function 'void read(int&)':
/in/foo.cc:60:2: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
  while((ch=getchar())<'0'||ch>'9');res=ch-48;
  ^~~~~
/in/foo.cc:60:36: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while'
  while((ch=getchar())<'0'||ch>'9');res=ch-48;
                                    ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:64:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,a,b,c;
          ^